Method for the deposition of monocrystalline or polycrystalline tin alloys on crystallographcially mis-matched or amorphous substrates

Abstract

A method for depositing a monocrystalline or polycrystalline tin alloy layer on an amorphous or crystallographically mis-matched substrate. The method includes selecting tin halide as the tin source; selecting an alloying metal precursor from germanium precursors, silicon precursors, and mixtures of germanium and silicon precursors; selecting a substrate from amorphous substrates and crystallographically mis-matched substrates; generating an inert gas plasma in a remote plasma generation reactor; contacting the inert gas plasma with the tin halide to provide an activated tin halide flow stream; contacting the inert gas plasma with the alloying metal precursor to provide an activated alloying metal flow stream; directing the activated tin halide flow stream and activated alloying metal flow stream to an alloy deposition chamber physically remote from the plasma chamber; and depositing the monocrystalline or polycrystalline tin alloy layer on the substrate in the deposition chamber.

What is claimed is: 
     
       1. A method for depositing a monocrystalline or polycrystalline tin alloy layer on a substrate, comprising the steps of:
 selecting tin halide as a tin source; 
 selecting an alloying metal precursor from the group consisting of disilane, trisilane, digermane, trigermane, and a mixture of two or more of the foregoing; 
 selecting a substrate from the group consisting of amorphous substrates and crystallographically mis-matched substrates, wherein the substrate is selected from the group consisting of TiN, and TiW; 
 generating an inert gas plasma in a remote plasma generation reactor, wherein the inert gas is xenon; 
 contacting the inert gas plasma with the tin halide to provide an activated tin halide flow stream; 
 contacting the inert gas plasma with the alloying metal precursor to provide an activated alloying metal flow stream; 
 directing the activated tin halide flow stream and activated alloying metal flow stream to an alloy deposition chamber physically remote from a plasma chamber; and 
 depositing the monocrystalline or polycrystalline tin alloy layer on the substrate in the alloy deposition chamber. 
 
     
     
       2. The method of  claim 1 , wherein the substrate is maintained at a temperature ranging from about 250° to about 450° during the deposition process. 
     
     
       3. The method of  claim 1 , wherein the deposition chamber is maintained at a pressure ranging from about 100 mTorr to about 10 Torr during the deposition process. 
     
     
       4. The method of  claim 1 , wherein the tin alloy is selected from the group consisting of Si 1−x Sn x , Ge 1−x Sn x , and Si 1−x−y Ge x Sn y , wherein x and y are greater than 0 and less than 1. 
     
     
       5. The method of  claim 1 , wherein the tin halide is SnCl 2 . 
     
     
       6. The method of  claim 1 , wherein a weight ratio of activated alloying metal precursor to activated tin halide flow ranges from about 0.5:1 to about 20:1. 
     
     
       7. A method for depositing a monocrystalline or polycrystalline tin alloy layer on a substrate, comprising the steps of:
 selecting SnCl 4  as a tin source; 
 selecting an alloying metal precursor from the group consisting of disilane, trisilane, digermane, trigermane, and a mixture of two or more of the foregoing; 
 selecting a substrate from the group consisting of TiN, and TiW; 
 generating a helium plasma in a remote plasma generation reactor; 
 contacting the helium plasma with the SnCl 4  to provide an activated SnCl 4  flow stream; 
 contacting the helium plasma with the alloying metal precursor to provide an activated alloying metal flow stream; 
 directing the activated SnCl 4  flow stream and activated alloying metal flow stream to an alloy deposition chamber physically remote from a plasma chamber; and 
 depositing the monocrystalline or polycrystalline tin alloy layer on the substrate in the alloy deposition chamber, 
 wherein a weight ratio of activated alloying metal precursor to activated SnCl 4  flow ranges from about 0.5:1 to about 20:1. 
 
     
     
       8. The method of  claim 7 , wherein the substrate is maintained at a temperature ranging from about 250° to about 450° during the deposition process. 
     
     
       9. The method of  claim 7 , wherein the deposition chamber is maintained at a pressure ranging from about 100 mTorr to about 10 Torr during the deposition process. 
     
     
       10. The method of  claim 7 , wherein the tin alloy is selected from the group consisting of Si 1−x Sn x , Ge 1−x Sn x , and Si 1−x−y Ge x Sn y , wherein x and y are greater than 0 and less than 1.